When "No RDR" is checked on a port forward, hide fields that do not apply.
When "No RDR" is checked on a port forward; Redirect target IP, Redirect target port, and Filter rule association have no meaning and probably should be hidden. Also, the filter rule association should automatically be changed to none in the configuration when "No RDR" is checked. Pass is invalid on a no rdr and an associated firewall rule has no meaning, because traffic is not being redirected to the target.
Hide redirect and filter rule association fields when "no rdr" is checked. Ticket #570